Cadillac Cts 2004 - Carputer Project

12-16-2006, 10:22 AM

THE CAR

Iím the proud owner of a 2004 Cadillac CTS (V6 engine and 181 HP). Itís black raven and Comfort finished, what in Spain means base equipment (no sunroof, no leather, no navigation). As you are aware all the CTS versions between 2003 and 2007 are basically the same, until the release of the brand new model this year.

THE PROJECT

I started thinking about upgrading the audio system once I realized the original is very basic and it doesnít offer an auxiliary input to connect an external source such an iPod or any other MP3 player. I know there are original CD changers and navigation systems but they donít have that aux input either. In the USA you can add an external source through the Xm radio device but in Spain that system is not very common so Cadillac doesnít offer it.

You can buy the navigation system via internet but the wiring job looked too hard to me and the fact that I would loose some functions anyway finally made me give this idea up. I turned my eyes to Cadillac then just in case they could give me a solution but they stated that itís not possible to install the navigation unit if the vehicle has not the pre-wiring from factory (??). Cadillac in Spain offers an Alpine solution at Ä 3,500.00 with an In-Dash touch screen and a DVD player but you must sacrifice the DIC information.

Too bad and too expensive, so I thought for a while about an aftermarket system to be installed inside the radio chassis. I donít like in-Dash solutions so my option was a double din system like the one described at:

Reaching this point, with a lot of DIY no matter what I decided to do, I thought that a computer would do it better because I could play all the existing audio and video formats, use the GPS navigation, internet connection, Bluetooth, a hard disk to store thousands of files, etc ..

There are loads of information via internet about how to integrate a computer in your car, but 2 guys had already took to reality what I have in mind:

The first thing to get the radio out from the car is to pull the air vents and the climate control apart. You can do it with your own hands but itíll be better if you use some kind of flat trowel. The radio is only fitted to the chassis with 4 bolts and after unscrewing them you must disconnect the ISO connectors plugged at the back side of the unit. Depending on which system you had the connectors panel may change.

The front face is a plastic piece fitted by 4 torx screws and 2 red connectors that interface with the main board inside the radio chassis. Once you disconnect them, you will see 3 different PCBs, one bigger for the DIC panel and 2 side boards for the control knobs. They are fitted with torx screws to a plastic mount as well. When all the parts are pulled apart, you can realize the actual size of the plastic you can cut off to room the screen bezel. Though I wanted to keep the original function keys, the guys I paid to do the job misunderstood me so they cut them off too so I had to change my plans a little. Finally I kept the buttons at the screen bezel so I could change the video source to get the images from the rear camera or turn it off manually.

Since I couldnít get a spare radio in the same colour mine was so I had to perform some extra jobs like sanding and painting, so if you intend to do it the way I did do not make the same mistake. It looks great at the end, but it makes you waste a whole week.

Comment

I am curious. Why couldnt you use the unused factory cd inputs for audio from the PC? This would be easy to do and you could keep the factory radio in tact for am/fm. All you would have to do is switch the factory radio to CD for the carputer audio to work.

In my case I would rather do that because I have an '05 cts which has XM built in.

Also, There should be enough room to install your cd/dvd rom (barely) in the dash above or below the 7". Were there any other issues you ran into that prevented this? Well one thing I notice is that you wouldnt be able to use the lcd bezel because it is too wide. Good luck on your project. I will probably have a lot more questions once I get started on mine. -r0xxx

Comment

What I'm doing is to take the sound from the sound card through 3 minijack to RCA cables. Remember that Epia MOBOs allow you to convert the "mic in" and "audio in" ports to out in order to get 5.1 sound. I'm keeping all the DIC info and the radio tuner as well. I'm only losing the original CD player.
How will you send the sound to the head unit CD input? If you do so, will the navigator voices be available when listening the radio? I don't think so ... but if you have a solution for this I would change my mind.
Have a look to the previous projects above, they were able to use the bezel and I'm doing that as well. The 7" touchscreen sizes the whole front, so there is no space for the DVD/CD slot.
I wouldn't recommend in-dash solutions because you will have problems at the end of the day.

Comment

I would imagine that the the audio wires for the CD player can be found in the cable between the radio and the cd player. Since you wont be using that cable, you should be able to hook up your audio out from your pc and splice it to this cable. You would need a wiring diagram of the radio which you can find at cadillacfaq.com.

You are right you would not be able to use audio from the NAV while the radio is playing but I dont see this as a big disadvantage. There is a button on the steering wheel of the CTS that lets you cycle between radio and cd (carpc). I like this option better than cutting the curcuit board of the radio like mattbai did. I would want to talk to him before I start on my project.

You said you bought a spare radio so you can return the dash to factory if need be. That is a great idea and I would like to do the same but a few questions...
Where did you get another radio and how much did you pay?
Does cadillac put any antitheft devices on the radio where they lock up if power is removed? That would suck if you had to call the factory everytime you change the radio.

I am going to try my hardest to find a way to get the dvd player to fit in the dash somehow.

Comment

The screen can be fitted using the original clamps at the bezel, and then we must locate the rest of the PCBs. Be sure they will not move using velcro (or any other means).
I connected the power to ACC, using some of the empty fuses at the box under the backseat ( I wouldn't recommend to use the climate control to get power). The Lilliput has USB and VGA connections for the tactile function and the image. In addition we will use the second video input to connect a rear camera, powered by ACC as well.
The camera is quite big (the one I liked by Alpine is Ä 300 and works even after is submerged in a glass of water). It's 120ļ angle and IR vision (0 Lux) so it's a good and cheap option). I'm locating it just above the plate and I will protect it with a PC sheet so it cannot be damaged by "accident".

Comment

The chassis is a 6 walls box that can be easily taken to pieces. The front wall is again fitted by torx screws but the upper and bottom walls are fitted by pressure flanges. Inside the chassis we have the CD player and the radio main board and both must be fully disassembled to have room enough to locate the computer components.
Itís all about screws so I will not explain the process. However the radio antenna is soldered to the chassis so we must unsolder it. If you are not going to use the original radio later you donít have to solder it again, but I did it because I wanted to.

Since the Epia board is too big for the chassis, we must locate it vertically and that affects the rest of the components. I did it this way:

Hard disk and M2 power supply screwed to the back wall.
Mother board screwed to the side walls and the I/O panel headed to the bottom.
Radio main board screwed to the front wall, inside the chassis. The connector panel is headed to the bottom too.

Be careful to keep the holes clear in order to allow the cables pass through and avoid any kind of contact with the chassis, so use plastic bushings or any other means when screwing the components. The bushings will be useful to cushion the vibrations as well.

CONNECTIONS

The touch screen is connected to the Epia via USB (to act as a mouse and keyboard) and the VGA port. You can get the power from any switched source (I wouldnít recommend to use the climate) but we used the fuse panel located under the back seats. Since I will not use the audio, I cut the speaker and the RCAs off.

The video in connector is used for the rear camera, so you will be able to switch from the PC to the camera with the front PC/AV button of the screen. I used a 120ļ angle waterproof camera, itís good and cheap but huge (3.5 cm diameter) so you can look for a minuscule but expensive Alpine model that works even inside a glass full of water if you can afford it (Ä 300).

I recommend you to use one of the back USB connectors to plug the GPS antenna because I found some problems to configure it when I plugged it through the HUB at the glove box. I wanted to locate the antenna inside the central air vents, but it wasnít able to get signal through the plastic (at least mine), so itís now over the dash board.

I headed the USB cable for the HUB behind the glove box and I practised some holes to pass the cables for the CD/DVD combo, so everything is hidden from outside. Inside the glove box we have the combo, Bluetooth, WiFi, TV USB, Memory Card reader and some available ports to plug any other device.

I'm using a Parrot 3100 device (inside the ashtray) to manage my phone call. It works great so I will not insist about PhoCo.

The idea is to use 2 parallel relays so you can switch from a source to the other by a button at the central console. Since the signal from the PC is too low, you must use a 2 channels amplifier between the computer and the harness.

Comment

At last I've got the PC installed and working. I only have to configure a couple of things (TV and POIs). I'm working on a post to describe the custom harness and the way we connected that it's the key for this project and I'm sure you will apreciate.